REPORT OF A COMPARISON OF ROUGHNESS MEASUREMENTS

Abstract

Roughness measurements were taken in 12 institutes and 3 companies manufacturing surface measuring instruments in 9 EC countries. The articles measured were a depth adjusting standard, 3 PTB rough standards with irregularly ground profiles and 4 LCA 'etalons de rugosite' (roughness standards) with turned profiles. A great diversity of measuring instruments was used in the 15 laboratories. On the depth adjusting standard the groove depths were measured. On the rough standards the mean roughness value R(a), the averaged roughness depth R(z) and the maximum roughness depth R(max) were measured under conditions clearly defined in DIN 4768 Sheet 1. Analysis of the 375 results showed deviations from the reference values to be within the following ranges: Depth adjusting standard: - 6.5% PTB rough standard: - 10% Etalons de rugosite: - 15% Detailed analysis of technical details of the equipment used indicates that there were systematic differences in the measurement of small R(z) values.